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4. TROUBLE SHOOTING
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Only for training and service purposes
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4.7 Power ON Troubleshooting
Power On sequence is :
PWR key press -> KPDPWR_N (QSC6270 KPDPWR_N pin(AA10)) go to low(TP1) -> QSC6270 Power Up -> VREG_
MSMC_1.2V(TP2), VREG_RF1_2.3V(TP3), VREG_MSME_1.8V(TP4), VREG_MSMP_2.6V(TP5), VREG_RF2_1.4V(TP6), VREG_
TCXO_2.85V(TP7) power up and system reset assert to MSM -> Phone booting and PS_HOLD assert to PMIC
START
TP1 Battery voltage. higher
than 3.20V?
Change or charging the Battery
No
Yes
Change the main board
TP1 go to low
when key press?
Check the Key Dome
No
Yes
TP2~TP7
power up?
Change the main board
No
Yes
Is clock ok?
TP8 : 32.768KHz
TP9 : 19M
Check the TCXO & Sleep Cystal
No
Yes